/**
 * Moondance UML modeling tool
 * 
 * This program is free software; you can redistribute it and
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 3
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

package ro.pub.cs.se.moondance.directedit;

import org.eclipse.jface.viewers.ICellEditorValidator;

import ro.pub.cs.se.moondance.model.VisibilityType;

/**
 * ICellValidator to validate direct edit values in the attribute label
 * Collaborates with an instance of ValidationMessageHandler
 */
public class AttributeNameTypeCellEditorValidator implements
		ICellEditorValidator {

	private ValidationMessageHandler handler;

	/**
	 * @param validationMessageHandler
	 *            the validation message handler to pass error information to
	 */
	public AttributeNameTypeCellEditorValidator(
			ValidationMessageHandler validationMessageHandler) {
		this.handler = validationMessageHandler;
	}

	/**
	 * @param validation
	 *            of attribute name
	 * @return the error message if an error has occurred, otherwise null
	 */

	// visiblity <<static>> name : type[multiplicity] = initialValue
	public String isValid(Object value) {
		String string = (String) value;
		String firstPart, secondPart;
		if (string.length() == 0) {
			String text = "Attribute definition should include at least a name";
			return setMessageText(text);
		}

		int colonIndex = string.indexOf(':');
		if (colonIndex >= 0) {
			firstPart = string.substring(0, colonIndex);
			secondPart = string.substring(colonIndex + 1);
		} else {
			firstPart = string;
			secondPart = "";
		}
		String[] result = firstPart.split("\\s");

		switch (result.length) {
		case 1:// name || pattern || visiblity
			if (result[0].startsWith("<<") && result[0].endsWith(">>")) {// pattern
				String pattern = result[0].substring(2, result[0].length() - 2);
				if (!pattern.equals("static")) {
					String text = "Invalid pattern. The valid format is: visiblity <<static>>  name:type[multiplicity]=initialValue";
					return setMessageText(text);
				}
			} else {// name || visibility
				/*
				 * if (ForbiddenIdentifierNames.contains(result[0])) { String
				 * text =
				 * "Attribute name is an invalid identifier. Do not use java keywords as attribute names."
				 * ; return setMessageText(text); }
				 */
			}
			break;
		case 2: // visibility name || visibility pattern || pattern name
			if (result[0].startsWith("<<") && result[0].endsWith(">>")) {// pattern
				// name
				String pattern = result[0].substring(2, result[0].length() - 2);
				if (!pattern.equals("static")) {
					String text = "Invalid pattern. The valid format is: visiblity <<static>>  name:type[multiplicity]=initialValue";
					return setMessageText(text);
				}
				if (ForbiddenIdentifierNames.contains(result[1])) {
					String text = "Attribute name is an invalid identifier. Do not use java keywords as attribute names.";
					return setMessageText(text);
				}
			} else {// visibility name || visibility pattern
				if (!VisibilityType.contains(result[0])) {
					String text = "Invalid visibility type. Permissible types are: "
							+ VisibilityType.getTypes();
					return setMessageText(text);
				}
				if (result[1].startsWith("<<") && result[1].endsWith(">>")) {// pattern
					String pattern = result[1].substring(2,
							result[1].length() - 2);
					if (!pattern.equals("static")) {
						String text = "Invalid pattern. The valid format is: visiblity <<static>>  name:type[multiplicity]=initialValue";
						return setMessageText(text);
					}
				} else {// name
					if (ForbiddenIdentifierNames.contains(result[1])) {
						String text = "Attribute name is an invalid identifier. Do not use java keywords as attribute names.";
						return setMessageText(text);
					}
				}
			}
			break;
		case 3: // visibility pattern name
			if (!VisibilityType.contains(result[0])) {
				String text = "Invalid visibility type. Permissible types are: "
						+ VisibilityType.getTypes();
				return setMessageText(text);
			}
			if (result[1].startsWith("<<") && result[1].endsWith(">>")) {
				String pattern = result[1].substring(2, result[1].length() - 2);
				if (!pattern.equals("static")) {
					String text = "Invalid pattern. The valid format is: visiblity <<static>>  name:type[multiplicity]=initialValue";
					return setMessageText(text);
				}
			}
			if (ForbiddenIdentifierNames.contains(result[2])) {
				String text = "Attribute name is an invalid identifier. Do not use java keywords as attribute names.";
				return setMessageText(text);
			}
			break;
		}
		if (secondPart.length() > 0) {
			int equalIndex = secondPart.indexOf('=');
			if (equalIndex > 0) {
				@SuppressWarnings("unused")
				String initialValue = secondPart.substring(equalIndex + 1);
				/*
				 * if (initialValue.length() == 0) { String text =
				 * "Initial value missing. The valid format is: visiblity <<static>>  name:type[multiplicity]=initialValue"
				 * ; return setMessageText(text); }
				 */
				secondPart = secondPart.substring(0, equalIndex);
			}

			int openedSquareBracketIndex = secondPart.indexOf('[');
			if (openedSquareBracketIndex > 0) {
				int closedSquareBracketIndex = secondPart.indexOf(']');
				if (closedSquareBracketIndex > 0) {
					String multiplicity = secondPart.substring(
							openedSquareBracketIndex + 1,
							closedSquareBracketIndex);
					try {
						@SuppressWarnings("unused")
						int multiplicityValue = Integer.parseInt(multiplicity);
					} catch (NumberFormatException nfe) {
						String text = "Invalid multiplicity value. It should be an integer.";
						return setMessageText(text);
					}
					if (secondPart.length() == 0) {// attribute has no type
						String text = "Attribute type missing. The valid format is: visiblity <<static>>  name:type[multiplicity]=initialValue";
						return setMessageText(text);
					}

					secondPart = secondPart.substring(0,
							openedSquareBracketIndex);
				}
			}
		}

		return unsetMessageText();
	}

	private String unsetMessageText() {
		handler.reset();
		return null;
	}

	private String setMessageText(String text) {
		handler.setMessageText(text);
		return text;
	}
}
